This application claims the priority of German Patent Application No. 100 40 800.1 filed Aug. 21, 2000, which is incorporated herein by reference.
The invention relates to a bomblet fuze for bomblets used in projectiles and missiles, which are ejected following a specified flight interval, at an altitude of several hundred meters and become effective upon impact with the ground or another target.
It is known to use a bomblet fuze, such as the M223 that is activated upon impact with relatively hard targets because of its inertia-dependent operation. However, such fuzes are subject to a high number of malfunctions when impacting with soft ground, for example, the desert, sand and snow. As a result, numerous dangerous duds that pollute the terrain are created, which is of particular importance to follow-up units.
Also known are bomblet fuzes provided with pyrotechnical self-destruct units in addition to the impact detonator, which is similar to the one for the M 223. These additional pyrotechnical self-destruct units are very involved and costly because long burning times of up 40 seconds and more must be realized within a small area. They also have the disadvantage that with frequently occurring shorter flight times, bomblets not ignited upon impact remain on the ground for relatively long periods before they are detonated with the pyrotechnical ignition cord. Follow-up units must wait during these times (with reserve).
It is the object of the invention to provide a bomblet fuze with a self-destruct feature, which is activated immediately following impact with an optional target (even a soft target such as sand and snow) and not following a constant time interval after the ejection. The fuze should be considerably cheaper to produce, as compared to pyrotechnical solutions, which is of enormous importance given the large quantity for each carrier.
Technically, this object generally is achieved according to the invention with a priming unit consisting of several nested casings, which are fitted one into the other and are provided with priming springs. More specifically, the above object generally is achieved according to the present invention by a bomblet fuze that comprises:
a fuze housing having a cylindrical interior that is open at one end and has an end well at its opposite end with a central or axial opening for a firing pin;
a detonator carrier disposed within the housing adjacent its open end;
a firing pin axially disposed in the housing ant having a firing end facing the detonator carrier and an opposite end that extends out of the housing via the opening and is connected to a stabilizing band.
first, second and third nested casings, each being open at one end and closed at its other end by a respective end wall having an opening for the firing pin, with the first casing having its open end facing the open end of the housing and a side-wall whose outer surface is connected to an inner wall of the housing via a screw connection such that the first casing can move axially relative to the housing from a first position where the firing end of the firing pin is adjacent the detonation carrier and a second position where the firing end of the firing pin is spaced from the detonation carrier and the end wall of the first casing abuts said end wall of said housing, with the second casing being disposed in the first casing with its open end facing the open end of the housing and of the first casing, and being connected to the first casing for relative axial movement via a normally compressed propulsion spring tending to move the second casing in an axial direction toward the open end of the housing, and with the third casing being disposed in the second casing with its end wall facing the open end of the housing and being connected to the firing pin for movement therewith;
a priming spring disposed in the third casing between the closed end wall of the second casing and the closed end wall of the third casing for moving the third casing and said firing pin toward the detonator carrier disposed at the open end of the housing;
an inwardly tapered conical bore formed in the side walls of the second and third casings at a position normally within the first casing near the open end of the first casing; and
a ball disposed in the conical bore of the second and third casings for preventing relative movement between the second and third casings while maintaining the priming spring in a compressed state, whereby, following unscrewing of the first casing, striking a target or the ground causes axial movement of the second and third casings by the propulsion spring and inertial forces sufficient to release the ball and permit the third casing and the firing pin to move axially and strike the detonator carrier.
One exemplary embodiment is shown in the FIGURE and is used in the explanation below.